This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. NLSL is a non linear least squares program for fitting CW spectra based on microscopically order but macroscopically disorder (MOMD) model, and NLSL.SRLS is a non linear least squares program for fitting multi-frequency CW spectra based on slowly relaxing local structure (SRLS) model A service request was received from Mr. Deniz Sezer to generate ESR spectra from the NLSL and NLSL.SRSL programs from ACERT website. These spectra were compared with those from MD simulations of nitroxide spin labels.